Driver-data structure.
typedef struct _DRIVDATA {
  LONG     cb;                /*  Length. */
  LONG     lVersion;          /*  Version. */
  CHAR     szDeviceName[32];  /*  Device name. */
  CHAR     abGeneralData[1];  /*  General data. */
} DRIVDATA;
typedef   DRIVDATA   * PDRIVDATA ;